ok that is not a good sign but may be the place to start
battery acid is very bad, especially if the motor has a bearing sensor in it.
I would definatly pull that motor and send it out to a motor repair shop and have it thoroughly checked out and rebuilt.
If the acid contamination is too severe though you may wind up having to replace the whole motor if the acid damaged the fields insulation.
I had a Cat A/C E4000 truck do me almost the exact same way as this, it ran me around in circles for a whole day and a half worth of troubleshooting, replacing the logic unit power board and finally finding that the battery overflowed and got acid all over the pump and drive motors, it totally trashed the pump motor due to the acid being so strong because it was a brand new machine.
The operator overfilled the battery before charging and when he did charge it the acid boiled out and went everywhere, ruined their floor and everything.
I would definitely have that motor looked at and repaired, and be prepared, there may be more issues with the fore mentioned controller, the acid could have shorted the circuits and caused damage elsewhere such as in the controller.